Move setDataSource to QgsMapLayer

also setter and getter for providerType

python/core/auto_generated/qgsmaplayer.sip.in

@@ -966,6 +966,31 @@ Write just the symbology information for the layer into the document
 .. versionadded:: 2.16
 %End
 
+
+    virtual void setDataSource( const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, bool loadDefaultStyleFlag = false );
+%Docstring
+Updates the data source of the layer. The layer's renderer and legend will be preserved only
+if the geometry type of the new data source matches the current geometry type of the layer.
+
+Subclasses should override this method: default implementation does nothing.
+
+:param dataSource: new layer data source
+:param baseName: base name of the layer
+:param provider: provider string
+:param options: provider options
+:param loadDefaultStyleFlag: set to true to reset the layer's style to the default for the
+                             data source
+
+.. seealso:: :py:func:`dataSourceChanged`
+
+.. versionadded:: 3.6
+%End
+
+    QString providerType() const;
+%Docstring
+Returns the provider type (provider key) for this layer
+%End
+
     QUndoStack *undoStack();
 %Docstring
 Returns pointer to layer's undo stack
@@ -1212,6 +1237,7 @@ Returns true if the refresh on provider nofification is enabled
 .. versionadded:: 3.0
 %End
 
+
   public slots:
 
     void setMinimumScale( double scale );
@@ -1432,6 +1458,15 @@ Emitted when layer's flags have been modified.
 .. seealso:: :py:func:`flags`
 
 .. versionadded:: 3.4
+%End
+
+    void dataSourceChanged();
+%Docstring
+Emitted whenever the layer's data source has been changed.
+
+.. seealso:: :py:func:`setDataSource`
+
+.. versionadded:: 3.5
 %End
 
   protected:
@@ -1535,6 +1570,11 @@ Read style data common to all layer types
 .. versionadded:: 3.0
 %End
 
+    void setProviderType( const QString &providerType );
+%Docstring
+Sets the ``providerType`` (provider key)
+%End
+
 
     void appendError( const QgsErrorMessage &error );
 %Docstring
@@ -1563,6 +1603,8 @@ Checks whether a new set of dependencies will introduce a cycle
 %End
 
 
+
+
 };
 
 QFlags<QgsMapLayer::LayerFlag> operator|(QgsMapLayer::LayerFlag f1, QFlags<QgsMapLayer::LayerFlag> f2);

src/core/qgsmaplayer.cpp

@@ -1573,6 +1573,21 @@ bool QgsMapLayer::writeStyle( QDomNode &node, QDomDocument &doc, QString &errorM
   return false;
 }
 
+void QgsMapLayer::setDataSource( const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, bool loadDefaultStyleFlag )
+{
+  Q_UNUSED( dataSource );
+  Q_UNUSED( baseName );
+  Q_UNUSED( provider );
+  Q_UNUSED( options );
+  Q_UNUSED( loadDefaultStyleFlag );
+}
+
+
+QString QgsMapLayer::providerType() const
+{
+  return mProviderKey;
+}
+
 void QgsMapLayer::readCommonStyle( const QDomElement &layerElement, const QgsReadWriteContext &context,
                                    QgsMapLayer::StyleCategories categories )
 {
@@ -1818,6 +1833,11 @@ bool QgsMapLayer::isReadOnly() const
   return true;
 }
 
+void QgsMapLayer::setProviderType( const QString &providerType )
+{
+  mProviderKey = providerType;
+}
+
 QSet<QgsMapLayerDependency> QgsMapLayer::dependencies() const
 {
   return mDependencies;

src/core/qgsmaplayer.h

@@ -38,6 +38,7 @@
 #include "qgslayermetadata.h"
 #include "qgsmaplayerstyle.h"
 #include "qgsreadwritecontext.h"
+#include "qgsdataprovider.h"
 
 class QgsAbstract3DRenderer;
 class QgsDataProvider;
@@ -886,6 +887,29 @@ class CORE_EXPORT QgsMapLayer : public QObject
     virtual bool writeStyle( QDomNode &node, QDomDocument &doc, QString &errorMessage, const QgsReadWriteContext &context,
                              StyleCategories categories = AllStyleCategories ) const;
 
+
+    /**
+     * Updates the data source of the layer. The layer's renderer and legend will be preserved only
+     * if the geometry type of the new data source matches the current geometry type of the layer.
+     *
+     * Subclasses should override this method: default implementation does nothing.
+     *
+     * \param dataSource new layer data source
+     * \param baseName base name of the layer
+     * \param provider provider string
+     * \param options provider options
+     * \param loadDefaultStyleFlag set to true to reset the layer's style to the default for the
+     * data source
+     * \see dataSourceChanged()
+     * \since QGIS 3.6
+     */
+    virtual void setDataSource( const QString &dataSource, const QString &baseName, const QString &provider, const QgsDataProvider::ProviderOptions &options, bool loadDefaultStyleFlag = false );
+
+    /**
+     * Returns the provider type (provider key) for this layer
+     */
+    QString providerType() const;
+
     //! Returns pointer to layer's undo stack
     QUndoStack *undoStack();
 
@@ -1077,6 +1101,7 @@ class CORE_EXPORT QgsMapLayer : public QObject
      */
     bool isRefreshOnNotifyEnabled() const { return mIsRefreshOnNofifyEnabled; }
 
+
   public slots:
 
     /**
@@ -1253,6 +1278,15 @@ class CORE_EXPORT QgsMapLayer : public QObject
      */
     void flagsChanged();
 
+    /**
+     * Emitted whenever the layer's data source has been changed.
+     *
+     * \see setDataSource()
+     *
+     * \since QGIS 3.5
+     */
+    void dataSourceChanged();
+
   private slots:
 
     void onNotifiedTriggerRepaint( const QString &message );
@@ -1340,6 +1374,9 @@ class CORE_EXPORT QgsMapLayer : public QObject
     void readCommonStyle( const QDomElement &layerElement, const QgsReadWriteContext &context,
                           StyleCategories categories = AllStyleCategories );
 
+    //! Sets the \a providerType (provider key)
+    void setProviderType( const QString &providerType );
+
 #ifndef SIP_RUN
 #if 0
     //! Debugging member - invoked when a connect() is made to this object
@@ -1400,6 +1437,10 @@ class CORE_EXPORT QgsMapLayer : public QObject
     bool mIsRefreshOnNofifyEnabled = false;
     QString mRefreshOnNofifyMessage;
 
+    //! Data provider key (name of the data provider)
+    QString mProviderKey;
+
+
   private:
 
     virtual QString baseURI( PropertyType type ) const;